0.7.0-alpha: The Laser Focus, the Redstone Lens and true mirrors

Lasers

• Redstone Lens (action): gives what the beam ends on a redstone signal of 1 to 15, strong or weak. Set it to give it always, to
  send on the signal its own block gets, or as a level emitter: while the Laser Ports up the light hold fewer than a
  count of an item, or that many or more (on a logistics beam, counted in its network). A Laser Focus it reaches is switched as by a wired signal, and the light it
  then passes on carries the signal further.
• Isolator Lens: two new switches. It can stop power (nothing past it is charged, though what the light does
  is still paid for), and pass a Redstone Lens's signal, which it stops by default.
• A Clear Laser Focus no longer passes light straight out through an Emitter on its far face.
• A cut or other work paid for by several sources through a Focus Emitter no longer stalls just short of done (stuck
  at 99%).
• A sneaking click with an empty hand takes an Emitter's lens out before the Emitter. In creative, what comes off a
  Laser Focus goes into your inventory.
• Isolator Lens: the redstone switch is a redstone torch, lit while signals pass, and its filter is labelled.
• Isolator Lens: Pickup's items go back up through it only if it passes logistics, and one in a Focus Emitter now stops
  them too (it didn't).
• A Laser Port takes light only straight in by its back, and a Lens Mount no longer takes light at an angle.
• A Laser Focus block with no focus stops light at any attachment on the face it comes in or goes out by.
• Beams notice a block placed or broken on them the next tick, instead of within half a second, and cost far less to keep
  watch over: only a change light can't pass, or one where a beam ends, is looked at.
• Light lights up, at its full brightness, and goes dark as soon as it should: from an Emitter put down or switched
  on, and through each Laser Focus it reaches or stops reaching, not up to a second later.
• A Laser Focus that light meets on a Stand, Cover or Emitter shows no light leaving it.
• The Laser Focus replaces the Laser Relay. Put a Laser Focus down, then put attachments on its faces: Focus
  Stands (as many as you like, or none and it floats), Focus Emitters (each with its lens and redstone setting) and
  Focus Covers. A Clear Laser Focus also lets light pass straight through. Attachments can go on a block with no
  focus and do nothing until one goes in; a sneaking click (by hand or with a wrench) takes off the focus or an attachment and leaves the rest.
  The focus loses nothing: each Emitter takes the loss, 0.5% by default (relayLoss), and mirrors 0.25%
  (mirrorLoss). Relays in your world become a Laser Focus with a Stand and their Emitters, lenses and redstone
  settings kept.
• Logistics Receptacles are Laser Focus attachments: several on one focus, each serving its own inventory. On a
  Clear Laser Focus light passes through as before. Receptacle blocks become a Clear Laser Focus with a Receptacle,
  settings kept.
• Cavity Mirrors are Laser Focus attachments: several on one focus, each with its own cavity. What they hold
  leaves by the focus's Emitters. Cavity Mirror blocks become a Laser Focus with a Stand, the plate and their
  Emitters, holding what they held. An unpaired one no longer acts as a mirror, and an
  Emitter facing back no longer closes a cavity: only a mirror does.
• Straight light no longer gets into a Laser Focus by a face with an Emitter (diagonal light still does).
• A Prism links to the face you click: its light runs at any angle to the middle of that face and goes in by it,
  so you choose which side of a machine it charges, or a Laser Port's or Lens Mount's back. From a Prism that can't see
  that face, the light meets the side it comes to first, as any light would. A Laser Focus, Mirror or Prism is still lit at its middle (its focus). Links made before take the
  face facing the prism.
• Mirrors reflect like real ones. A beam bounces off a Laser Mirror and goes on as the same beam, with its own
  light: beams crossing one mirror never mix. A plate faces one of 42 ways: flat to a face, or turned 22.5° or 45°
  towards a neighbouring one. Click a face's middle for flat, the ring round it for 22.5°, the outer ring for 45°
  towards the side clicked; sneak-click to move the stand. Looking at a face outlines its parts, and a ghost shows where
  the plate would turn. A plate never faces towards its stand. Light now travels diagonally too (26 ways in all); what leaves a mirror
  is always one of them. Mirrors already placed keep the way they faced. Each bounce takes 0.25%.
• The Laser Splitter reflects off both sides and lets light through: one beam becomes two, each its own. It no
  longer joins beams into one. It can face straight on too. Light never leaves a mirror or splitter through its stand.
• Cavities round corners. A cavity's light can run round any number of plain Laser Mirrors, back off a flat one
  or into another Cavity Mirror: up to 16 blocks one way, each mirror counting as one. A splitter, or a mirror
  switched off, breaks it.
• Mirrors no longer show where light would go while holding a wrench or the Linker.
• An Interact Lens with nothing to do waits longer between tries, as Insert and Extract do (up to laserIdleSeconds),
  instead of trying everything it's sent every tick. Busy, it keeps its pace.

Reactor

• A storage bus reading a busy Reactor's Materialiser Port costs far less: an answer stands for a second while what it
  uses is still there, however else the Reactor changes, and planning is held to about 1 ms a tick (a bus listing 1,450
  slots every tick went from about 240 ms to under 2 ms). Things never asked about before can take a few seconds to show.
• Plans look items up faster, and the ME Superposition Port plans its trees without copying the whole stock for each,
  in at most about 1 ms a tick.